1. Field of the Invention
This invention concerns measurement of temperature of hot gases, in general. More specifically, it concerns an improvement for an arrangement with a pyrometer that is used to measure radiation from hot gases that are laden with entrained solids.
2. Description of the Prior Art
Pyrometers are used for measuring temperatures of hot atmospheres, such as the internal structure of a synthesis gas generator or the like, where the measurement involves reading the radiation from the hot atmosphere as it is measured by the pyrometer. Pyrometers deal with making radiation measurements which may then be translated into temperature. And, among various types of pyrometers there are those that measure total radiation and those that measure brightness and others that measure two-color or ratio measurements. Generally, the measurements involve determination of the energy radiated over the entire spectrum or over a narrow range of wavelength(s) being received and consequently the instruments for making these measurements are quite delicate and must be protected from high temperature conditions.
Heretofore, arrangements have been made such as the apparatus shown and described in U.S. Pat. No. 2,576,514, H. R. Bianco et al, issued Nov. 27, 1951. In the Bianco et al patent, an arrangement is provided to overcome the difficulty that developed where the atmosphere being measured by the pyrometer was a molten bath or slag or like high melting temperature substance. The patent applies a radiation pyrometer to overcome drawbacks encountered with the use of a thermocouple or an optical pyrometer.
The arrangement of the Bianco et al patent includes a sight tube with the mounting for a radiation pyrometer. The sight tube extends through the furnace wall and has an arrangement for cooling it. And, in that patent, the problem of having the hot molten liquid tend to block the inside end of the sight tube was overcome by providing a longitudinally movable sight tube so that the movement thereof would dislodge and break up any blockage tending to form over the end by the molten liquid.
In the applicants' invention there is provided an improvement for a combination that uses a pyrometer. It overcomes and avoids all the complications and additional equipment used in a system like that of the Bianco et al patent. Thus, it is an object of this invention to provide a relatively simple yet highly effective improvement for a system that employs a pyrometer with sight tube and related equipment. The system is used to make temperature measurements on the interior of a vessel containing hot gases laden with entrained solids that form molten slag.